1. Field of the Invention
The present invention relates generally to techniques for improving the performance of internal combustion engines. More particularly, the present invention provides a novel method and apparatus for enhancing such performance through the cooling of intake air immediately prior to combustion chamber entry.
2. Description of the Related Art
The efficiency of an internal combustion engine is affected by many variables. For example, the composition of the mixture of air and fuel introduced into the combustion chambers of an internal combustion engine significantly affects performance. To achieve optimum efficiency, the air/fuel mixture must be appropriately maintained at all levels of operation.
A number of modifications and enhancements have been made to conventional internal combustion engines in an effort to improve performance. For example, it is well known that increasing the volume of air and fuel entering the combustion chambers will result in improved performance. Turbochargers and superchargers are devices which utilize mechanical means to compress the air/fuel mixture just prior to introduction into the combustion chamber. This increases the density of the air/fuel mixture, which leads to superior performance relative to naturally aspirated (atmospherically charged) engines. However, the use of a turbocharger or supercharger tends to increase the temperature of the air/fuel mixture during compression. This temperature increase degrades volumetric efficiency (i.e., air/fuel mixture per unit volume) by reducing the density of the air/fuel mixture being introduced into the combustion chamber.
In contrast to turbocharged and supercharged engines, naturally aspirated engines draw air directly from the area surrounding the air inlet and filter system. Efforts have been made to improve volumetric efficiency by positioning this air inlet in locations remote to the remainder of the engine. That is, it has been attempted to reduce the ambient temperature of the air being drawn into the combustion chamber by remotely locating the point at which atmospheric air is collected. Unfortunately, such efforts have yielded only modest gains in volumetric efficiency.
Intercoolers have been known to improve the efficiency and performance of turbocharged and supercharged engines for some time. The intercoolers that have been employed to date for these applications have been in a form that is an additional component to the engine, requiring modification to the engine and/or the turbocharger or supercharger. Devices have been utilized which introduce into the air/fuel mixture other liquids in an attempt to cool the mixture prior to combustion. There have also been attempts to provide cooling jackets surrounding the air passages through which the air flows prior to entering the combustion chambers. In addition, devices using complex systems of utilizing the air conditioning and heating systems of a vehicle have been developed, but in a manner which does not ensure that all the air entering the carburetor or throttle body will benefit from the cooling effort.